- 目录
- 建筑石膏与胶凝材料
- 首页
天然火山灰质凝灰岩掺合料物化性能及火山灰活性特征研究
作者：蒋理1，李杨2，李家正2，林育强2
（1.华电西藏能源有限公司大古水电分公司，四川 成都 856200；
2.长江水利委员会长江科学院 材料与结构研究所，湖北 武汉 430010）
摘要：天然火山灰质凝灰岩可用作混凝土掺合料。借助偏光显微镜技术、XRF、XRD和SEM等手段，研究了凝灰岩的矿物组成、化学成分和颗粒形貌；采用活性指数、强度增长率和抗压强度比等指标，分析了凝灰岩掺量、养护龄期和水泥类型对砂浆抗压强度的影响。结果表明：凝灰岩含有大量的低温型硅铝质材料，矿物组成和玻璃质含量对火山灰活性有较大影响，其活性指数在28 d龄期前有增长，56 d龄期后变化较小，并且使用中热硅酸盐水泥测得的凝灰岩活性指数低于普通硅酸盐水泥。凝灰岩对砂浆后期强度的提高能力不足，建议复配其它掺合料共同使用。
关键词：凝灰岩；掺合料；火山灰活性；中热硅酸盐水泥
中图分类号：TU521.2+1 文献标识码：A 文章编号：1001-702X（2023）02-0086-05
Investigation of physical and chemical properties of tuff powder and its pozzolanic activity characteristics
JIANG Li1，LI Yang2，LI Jiazheng2，LIN Yuqiang2
（1.Huadian Tibet Hydropower Development Co. Ltd.，Chengdu 856200，China；
2.Yangtze River Scientific Research Institute，Material and Structure Research Department，Wuhan 430010，China）
Abstract：Natural pozzolanic tuff can be used as concrete. In this paper，mineral phase composition，chemical components and particle morphology of tuff powder are examined by petrographic identification，XRF，XRD and SEM. Moreover，the effects of tuff powder content，curing age and cement type on compressive strength of mortars are analyzed，employing activity index，strength growth rate and compressive strength ratio. Experimental results reveal that tuff powder contains a great amount of low-temperature silico-alumina materials，and the mineral composition and glass content possess a great influence on its pozzolanic activity. Activity index of tuff powder obtained by moderate heat Portland（P·MH） cement is a slightly lower than that of ordinary Portland（P·O） cement. What's more，tuff powder have limited ability to enhance long-term strength of mortar，and the content should be reduced and other mineral admixture should be combined when tuff powder is employed to substitute P·MH cement.
Key words：tuff powder，mineral admixture，pozzolanic activity，moderate heat portland cement